#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using pii = pair<int, int>;
#define rep(i, a, b) for (int i = (a); i <= (b); i++)
#define per(i, a, b) for (int i = (a); i >= (b); i--)
#define endl '\n'
const int N = 2e5 + 5;

ll n, k;

ll lowbit(ll x) { return x & -x; }
int main() {
  ios::sync_with_stdio(0), cin.tie(0), cout.tie(0);
  cin >> n >> k;
  ll sum = 0;
  while (__builtin_popcountll(n) > k) {
    sum += lowbit(n);
    n += lowbit(n);
  }
  cout << sum;
  return 0;
}